P. jirovecii colonization can be frequently detected in immunocompetent adults, which suggests that the general population could be a source of this infection.

Objectives-A self referred group of four workers from a factory producing scouring powder with a high silica content showed a surprisingly high number of features compatible with a connective tissue disease. Further subjects working at the same factory were subsequently studied to evaluate the relation between this exposure and the development of autoimmune processes. Methods-A total of 50 subjects (44 women, six men; mean (SD) age 43 7 (5 5) years; mean duration of employment 6*1 years) underwent a prospective study including clinical history and physical examination, an immunobiological study, HLA typing, radiological and functional oesophageal and respiratory examination, ophthalmological examination, and isotopic testing of salivary glands. Results-Symptoms of a systemic illness were present in 32 (64%) subjects: six with

In chronic obstructive pulmonary disease, high levels of airway and systemic inflammatory markers are associated with a faster decrease in lung function. Our study shows that patients colonized by Pneumocystis jiroveci have higher proinflammatory cytokine levels than do noncolonized patients. This suggests that Pneumocystis may play a role in disease progression.

Since mutations in the dihydropteroate synthase (DHPS) gene possibly associated with sulfonamide resistance have been reported in patients with Pneumocystis jiroveci (previously carinii) pneumonia, and since P. jiroveci colonization has been recently demonstrated in patients with chronic pulmonary diseases, the present study aimed to investigate the possible occurrence of P. jiroveci DHPS mutations in patients with chronic bronchitis. P. jiroveci colonization was detected in 15 of 37 non-selected patients with chronic bronchitis by amplifying the large subunit of the mitochondrial gene of the ribosomal RNA using nested PCR. DHPS mutations were demonstrated using touchdown PCR and restriction enzyme analysis in two of eight patients with chronic bronchitis and in two of six patients from the same region who had AIDS-associated Pneumocystis pneumonia. In all cases, mutations were observed in subjects with no prior exposure to sulfonamides. These data could have important implications for public health, since (i) P. jiroveci colonization could speed the progression of chronic bronchitis, and (ii) these patients, who are customary sputum producers, could represent a reservoir for sulfonamide-resistant strains with the potential ability to transmit them to immunocompromised hosts susceptible to Pneumocystis pneumonia.